The present invention relates to a perimeter for examining a state of a visual field of an examinee's eye.
When diagnosing disease such as glaucoma, examining (measuring) the state of the visual field (perimetry) is considered to be effective. As an apparatus for examining the state of the visual field (perimeter), such an apparatus is known in which a stimulation target (optotype) for examination is projected on a dome-shaped screen or is displayed on an electronic display unit such as a liquid crystal display to be presented to the examinee's eye fixing to (gazing at) a predetermined fixation point while varying a presentation position and presentation brightness (luminance) of the target, distribution of optical (visual) sensitivity at each examination point an a retina of the examinee's eye corresponding to each presentation position is examined (measured) by obtaining whether or not the examinee can perceive (visually recognize) the presented target. Then, according to this kind of perimeter, the examinee responds by pushing a response button when the examinee perceives the presented target.
However, it depends on the examinee's consciousness whether or not the examinee can perceive the presented target. Therefore, even if the examinee pushes the response button although the examinee cannot perceive the target, it is detected that the examinee could perceive the target, so that the precise examination result cannot be acquired.